Cordless blind apparatus

Abstract

The present invention provides a cordless blind apparatus that can be conveniently operated without a cord. The cordless blind apparatus includes: a roller that is fitted on a rotary shaft; a screen that is wound or unwound on the roller; a weight that is connected to the lower end of the screen and applies torque in a first direction in which the screen is unwound from the roller by the gravity; an elastic member that applies torque in a second direction in which the screen is wound, by applying elastic force to the roller; and a friction stopper assembly that generates friction force on the roller.

The invention claimed is: 
     
       1. A cordless blind apparatus comprising:
 a roller that is fitted on a rotary shaft; 
 a screen that is wound or unwound on the roller; 
 a weight that is connected to a lower end of the screen and applies torque in a first direction in which the screen is unwound from the roller by gravity; 
 an elastic member that applies torque in a second direction in which the screen is wound, by applying elastic force to the roller; and 
 a friction stopper assembly that generates friction force on the roller, 
 wherein the rotary shaft includes a first rotary shaft extending in the roller, and the friction stopper assembly includes a first rotary block coupled to the roller to rotate with the roller and generate friction on the first rotary shaft, 
 wherein the apparatus further comprises a friction member that is disposed on at least one of an outer side of the first rotary shaft and an inner side of the first rotary block to increase friction resistance, 
 wherein the friction member extends in a longitudinal direction of the first rotary shaft on the outer side of the first rotary shaft, and 
 wherein the friction resistance of the friction member changes in the longitudinal direction of the first rotary shaft. 
 
     
     
       2. The cordless blind apparatus of  claim 1 , wherein the friction force offsets a resultant force of the torque applied to the roller in the first direction and the torque applied to the roller in the second direction. 
     
     
       3. The cordless blind apparatus of  claim 1 , wherein the elastic member is a torsional elastic body that keeps elastic energy by elastically deforming when the roller is rotated. 
     
     
       4. The cordless blind apparatus of  claim 3 , wherein the torsional elastic body is a coil spring fitted on an outer side of the rotary shaft. 
     
     
       5. The cordless blind apparatus of  claim 1 , wherein the first rotary shaft has threads on the outer side to be a male screw, and the first rotary block has female threads on an inner side of a hole formed through a center thereof to be a female screw that is thread-fastened to the male screw. 
     
     
       6. The cordless blind apparatus of  claim 1 , wherein the friction member is an elastic body that elastically deforms between the first rotary shaft and the first rotary block and a thickness or an area of the friction member changes in the longitudinal direction of the first rotary shaft. 
     
     
       7. The cordless blind apparatus of  claim 1 , wherein the rotary shaft includes a second rotary shaft extending in the roller, and further includes a second rotary block fitted on the roller to rotate with the roller, and the elastic member is fixed to the second rotary block and the second rotary shaft at ends of the elastic member. 
     
     
       8. The cordless blind apparatus of  claim 1 , wherein the roller comprises a plurality of rollers arranged in parallel with each other, and the screen comprises a plurality of screens, the weight comprises a plurality of weights, and the elastic member comprises a plurality of elastic members that are provided to correspond to the rollers. 
     
     
       9. The cordless blind apparatus of  claim 8 , further comprising a
 connection hook disposed at least between the screens or between the weights, and the friction member is disposed on at least one of the rollers. 
 
     
     
       10. The cordless blind apparatus of  claim 9 , wherein the connection hook is slidably fitted in guide grooves formed on the weights. 
     
     
       11. A cordless blind apparatus comprising:
 a roller that is fitted on a rotary shaft; 
 a screen that is wound or unwound on the roller; 
 a weight that is connected to a lower end of the screen and applies torque in a first direction in which the screen is unwound from the roller by gravity; 
 an elastic member that applies torque in a second direction in which the screen is wound, by applying elastic force to the roller; and 
 a friction stopper assembly that generates friction force on the roller, 
 wherein the rotary shaft includes a first rotary shaft extending in the roller, and the friction stopper assembly includes a first rotary block coupled to the roller to rotate with the roller and generate friction on the first rotary shaft, 
 wherein the apparatus further comprises a friction member that is disposed on at least one of an outer side of the first rotary shaft and an inner side of the first rotary block to increase friction resistance, 
 wherein the friction member has serrations on a surface being in contact with the first rotary block or a surface being in contact with the first rotary shaft, and 
 wherein at least one of a height, a gap, and a shape of the serrations on the friction member changes in a longitudinal direction of the first rotary shaft, and wherein the friction member is configured to be removably attached to the first rotary shaft during assembly.